Chael is definitely the best coach they've had in recent seasons with the best roster the show's ever had...
However, I still believe that Chuck is worthy of being called the best coach because he has the best record of winners on the show, having gone 3-0.
I would make the same argument for Bisping if his record wasn't 3-1 (Jon Dodson KOing TJ Dillashaw being that 1).

I thought Tito was the first best one, so he gets my vote. It also happened to be against Shamrock and a season that had a ton of fighters that would go on to have UFC careers so that probably all helped to make Tito the first best one.